Jeff, Thanks for your response. I am
using the standard child_main() loop
in which select() is protected by the
mutex. The only difference is that the
parent is bound to a well known udp
port and so all children are monitoring
this well known port. Despite this mutex,
I see this behavior fairly consistently.
The frequency is more on solaris than on linux.
The crash that I saw was in apr_pool_alloc_init().
apr_lock_create() failed, although there were
not permissions problems and then apr_lock_destroy()
crashed while accessing a NULL pointer.
The relevant code fragment in apr_pool_alloc_init() is :
#if APR_HAS_THREADS
status = apr_lock_create(&alloc_mutex, APR_MUTEX, APR_INTRAPROCESS,
NULL, globalp);
if (status != APR_SUCCESS) {
apr_lock_destroy(alloc_mutex);
return status;
}
Thanks,
Shail
Jeff Trawick wrote:
>
> Shail Bhatnagar <[EMAIL PROTECTED]> writes:
>
> > I have observed that sometimes select()
> > returns a positive value to one or more processes
> > but only one is able to read UDP data.
>
> On every system I know of, select() wakes up every process/thread
> selecting on the same descriptor (e.g., UDP socket) when the condition
> is met (e.g., a datagram is ready to read).
>
> You'll want to use a mutex to ensure that only one process is in the
> select()+recvfrom() path at a time. Otherwise, the extra wakeups will
> hurt performance.
>
> But Apache already does this when there are multiple listening (TCP)
> sockets. Take advantage of that mutex.
>
> > The server is this case has been modified
> > to listen on a well known udp port.
> >
> > Does anybody have any clue ? The errno returned
> > by recvfrom() is 11 - resource temporarily unavailable.
> >
> > Secondly, is there a know crash on Solaris when
> > APR_HAS_THREADS is on. This is about httpd 2.0.16 beta.
>
> Justin Erenkrantz fixed a gethostbyname() issue with a threaded build
> on Solaris < 8. You may wish to try the latest code from CVS.
>
> --
> Jeff Trawick | [EMAIL PROTECTED] | PGP public key at web site:
> http://www.geocities.com/SiliconValley/Park/9289/
> Born in Roswell... married an alien...
